The present invention relates generally to a high-power pulsing apparatus and more particularly to a multiple repetitive resonant railgun power supply.
Many applications require power in the form of a train of high-power pulses. Included among these applications are high-repetition-rate particle accelerators and lasers, pulsed microwave generators, high-power high-resolution radar, induction heating systems and electromagnetic projectile launchers.
Electromagnetic projectile launchers such as railguns are under consideration for space and ground defensive weapons systems because they can accelerate projectiles to velocities much greater than conventional chemical guns. Railguns have demonstrated velocities of 10 km/s while chemical or gas guns obtain maximum velocities of 3 km/s. A projectile is accelerated in a railgun by a large current which travels along one rail to the projectile where it is conducted to the opposite rail through the projectile or a metallic plasma and returns to the current source. Projectile acceleration is due to the interaction of the large magnetic field between the rails and the current flowing through the projectile and is proportional to the square of the rail current. Because the acceleration falls off rapidly if the current decreases, the minimum acceleration time and the shortest barrel or rail length is obtained when a constant current is used to accelerate the projectile. Railguns require megampere level currents to accelerate projectiles with masses of interest.
In order to provide a relatively constant current to conventional railguns, a common inductive energy storage system is used in which the rail electrodes are in parallel with an opening switch. The inductor is charged to the magampere level current desired through the closed switch. The switch is opened by increasing the impedance of the current path which generates a large voltage and transfers the current to the rail electrodes. A conventional opening switch must absorb a large amount of energy and then hold off the large transient voltage generated by the increase in resistance. For these reasons, conventional inductive energy storage and opening switch systems have been operated only in single pulse and very low voltage systems at megampere current levels because the opening switch is difficult to build and operate.
Since great energy is required in many applications, the values of the energy storage components must be very large and therefore quite expensive and difficult to fabricate. By connecting a plurality of energy storage systems and railgun segments in series, the value of each energy storage component may be reduced to a more standard and readily obtainable size, or conversely the overall energy output may be greater. See for example, LA-8000-C, Proceedings Of The Impact Fusion Workshop, July 10-12, 1979, Los Alamos Scientific Laboratory, Los Alamos, N.M.
It is therefore an object of the present invention to provide a multiple high-power repetitive pulsing system capable of continuous operation.
It is another object of the present invention to provide a multiple high-power repetitive pulsing system wherein each opening switch function is performed with negligible energy loss.
It is yet another object of the present invention to provide a multiple repetitive resonant railgun power supply.